Intraocular implants, as used for replacement of the natural lens of the eye after removal of the latter to remediate cataracts, consist of a 6-7 mm. diameter magnifying lens (of approximately 60 diopters power as measured in air) in conjunction with peripheral loops or flanges designed to support the implant and maintain its centration in the optical axis of the eye.
A conventional method of manufacturing implants is to prepare, by machining and polishing, a circular lens of desired diameter from a suitable material such as polymethyl methacrylate, and then in subsequent operations, drill holes and attach supporting loops made of polypropylene or polymethyl methacrylate filaments. This method requires numerous operations and skilled labor to achieve satisfactory production. In another mode of manufacture, monolithic implants are produced using automatic mills to cut both the optic portion and supporting loops, followed by a lengthy polishing operation to achieve suitable optical surfaces on the implant. Both these methods suffer from the need for multiple operations and the use of polishing compounds which have been shown to be deleterious to the eye unless rigorously removed.
It is the object of this invention to produce directly monolithic implants which require little or no subsequent finishing operation by casting, polymerization or vulcanization of suitable monomer mixtures or prepolymer materials in an inexpensively produced closed mold system.